Lamp cap for luminescent tubes or fluorescent lamps



Feb. 13, 1940. J. LlsToN 2,190,364 LAMP CAP FOR LUM-INESCENT TUBES OR 'FLUORESGENT LAMPS A I yFiled Dec. 29, 1938' ATTORNEYS Patented Feb. 13, 1940 UNITED STATES PATENT OFFICE John Liston, Cleveland,

Lighting Corporati Ohio, assignor to Novelty on, Cleveland, Ohio Application December 29, 1938, Serial No. 248,261

. l 2 Claims. This invention concerns improvements in, or

relating to end caps for luminescent or fluorescent tubes or lamps.

y An object of the invention is to provide a lamp 3' cap which can be easily removed or replaced in exact position on the supporting bracket, thus allowing a burned out tube or lamp to be replaced by a new one without requiring readjustment of the cap when replaced.

A further object of the invention is to provide an instrumentality for accomplishing the above objects, whichl is simple in structure and use, eflicient in operation, and economical to manufacture.

'I'he invention and its aims and objectslwill be' clearly understood from the following descripl tion, taken in connection with the accompanying drawing, of one embodiment of the invention `herein given for illustrative purposes, the true 20 scope of the invention being more fully pointed out in the appended claims.

Infthe drawing: Figure 1 is an end elevation of the cap mounted on a conventional bracket. J 26 Figure 2 is a side elevation of the cap, shown in Figure 1, the luninescent tube or fluorescent lamp. is shown fragmentary.

Figure 3 is a side elevational view of the cap alone, shown in Figure 2, turned through 90 to 80 show the flanges thereof, with indentations in each ange, vand also aposition'ing rib in the in terior of the cap. j c

Figure 4 isa side elevation of another embodiment of a cap, showing by way of example, the a5 cap structure used when the supporting brackets are placed back to back, the luminescent tubes or fluorescent lamps are shown fragmentary.

Figure 5 is a side elevational view of the cap alone as shown in Figure 4, turned through 90 to show the indentations in each flange, also the yposition of the positioning rlbtherein.A

Similar reference numerals indicate the same parts throughout the several views.

Referring to the drawing, the lamp cap I0 '4 45! comprises a part encircling body Il of suitable` geometrical configuration, corrugated orotherwise, as shown at i2, having two vlongitudinally, extending flanges I3 vand I I bent outwardlyv as at I5 and I8. Each ange is provided withan indentation as shown. at I'I and i8. A

One end oi' the lamp cap is closed with a plate Il.

It will be noted, see-Figure l, at 2li and 2|, that thebwyvortion orthelamp capisrree from attachment with the plate for a short distance at each side-to allow the body portion to spread and contract slightly to accommodate brackets that might vary from the standard specification in manufacturing. This freedom from attachment of the encircling body from the plate also provides a mea'ns to permit clamping of the lamp cap on the bracket through the interaction ofthe flanges with the bracket through the inherent resiliency of the metal constituting the cap.

.The indentations in the similarly 'characterized flanges are s0@placed,`that when the cap is slipped on the bracket or fixture, the bracket is held in contact withthe inner surface 22 of the plate. The construction of the flanges and vthe position of'v .the indentations in the anges relative to the bracketl dually function to hold the cap in clamped relation with the bracket, and at the ,same time prevents endwise movement of the cap relative to the' bracket. y

'I'he rib 23 in the cap is provided to position the cap relative to the bracket and the luminescent or fluorescent tube, or lamp, so that the cap per se will permit a circulation of air around that portion of the tube or lamp partly encircled thereby so that the heat storing zone created by the cap becomes a heat yielding zone. The forward end 24 of the rib is inclined oil to a bevel-angle as at 25 so that therib will easily ride up and into place on the bracket. The cap is of a length `suiiicient to obscure the filament 28 in the tube or lamp as shown in Figure 2.

In the structure shown in Figures 4 and 5, the double cap 21 is provided with a positioning rib 28 having its ends 29 and 30 inclined oil to a bevel-angle as at 3| and 32 so that the rib will A easily ride up and into place on the bracket. The similar characterized flanges 33 and 34 are provided-with indentations 35, 36 and 31 and 38, see indentations in flanges\in Figure 5. 'Ihe indentations are provided to properly position the cap in relation to the brackets, when the brackets are placed back to back as shown in Figure 4. The conventional brackets are shown in Figures ,1, 2 and 4 at 39 and are all of the same general configuration and construction. Y

It will be understood that the caps are always of sufficient length to obscure the filament in4 l"the lamp or tube so that the lightl will beuniform throughout the lengthof the tube beyond the 'Ihe caps may lbe embellished to bring them into conformity with 'the principles of esthetics in the lighting xtureart.

It will be understood .that the cap shown in Figure 1 andin Figure 2 is interchangeable from left to right and vice versa.

' 'I'he luminescent tubes or uorescent lamps are shown fragmentary at 40 in Figures 2 and 4.

The luminescent tubes or iiuorescent lamps and xtures in or on which the same is mounted, are of standard construction and form no part of the present invention.

It isvbelieved that a rsum of the operation of the cap is unnecessary.

Although the foregoing description is necessarily of a detailed character, in order to dompletely set forth the invention, it is to be understood that the specific terminology is not intended to be restrictive or confining, and it is to be further understood that various rearrangements of parts and modification of structural detail may be resorted to without departing from the scope or spirit of the invention herein claimed.'.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination with a supporting bracket and a luminescent lamp, a cap comprising a part enclosing body portion terminating in lsymmetrically aligned nanges having indentations formed therein at a predetermined location relative to the suppOrting bracket, an end fixed in an end of the aforesaid enclosing body portion, and having opposite portions of the enclosing body -porfixed in the interior of the cap and extending into the body portion from the fixed end in the cap, and adapted to maintain the cap in spaced relationship with the bracket and the lamp.

2. In combination with supporting brackets and luminescent lamps, a cap comprising a part encircling body terminating in aligned flanges having spaced lindentationsV formed in each ange, a xed positioning rib in the part encircling body intermediate the length thereof, the positioning rib adapted to position the `cap relative to the brackets, the indentations formed iny the anges adaptedfto prevent movement of the cap when the cap is mounted on the brackets, the laterally extending portions of the cap be` yond. the .indentations being free from longitudinal support. JOHN LISTON.

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